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Commit fe2d5295 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

[CRYPTO] Fix boundary check in standard multi-block cipher processors 



The boundary check in the standard multi-block cipher processors are
broken when nbytes is not a multiple of bsize.  In those cases it will
always process an extra block.

This patch corrects the check so that it processes at most nbytes of
data.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b69aee04

crypto/cipher.c

+9 −3
Original line number Diff line number Diff line
@@ -191,6 +191,8 @@ static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, 
	u8 *iv = desc->info;

	unsigned int done = 0;



	nbytes -= bsize;



	do {

		xor(iv, src);

		fn(crypto_tfm_ctx(tfm), dst, iv);
@@ -198,7 +200,7 @@ static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, 


		src += bsize;

		dst += bsize;

	} while ((done += bsize) < nbytes);

	} while ((done += bsize) <= nbytes);



	return done;

}
@@ -219,6 +221,8 @@ static unsigned int cbc_process_decrypt(const struct cipher_desc *desc, 
	u8 *iv = desc->info;

	unsigned int done = 0;



	nbytes -= bsize;



	do {

		u8 *tmp_dst = *dst_p;
@@ -230,7 +234,7 @@ static unsigned int cbc_process_decrypt(const struct cipher_desc *desc, 


		src += bsize;

		dst += bsize;

	} while ((done += bsize) < nbytes);

	} while ((done += bsize) <= nbytes);



	return done;

}
@@ -243,12 +247,14 @@ static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst, 
	void (*fn)(void *, u8 *, const u8 *) = desc->crfn;

	unsigned int done = 0;



	nbytes -= bsize;



	do {

		fn(crypto_tfm_ctx(tfm), dst, src);



		src += bsize;

		dst += bsize;

	} while ((done += bsize) < nbytes);

	} while ((done += bsize) <= nbytes);



	return done;

}